The small-scale investigation, published in Nature Communications, sought the assistance of 52 people who lived with someone who had just contracted Covid-19.
Those who created a “memory bank” of particular immune cells after a cold to help avoid future attacks appeared to be less likely to develop Covid.
Immunizations will continue to be necessary, according to experts, and no one should rely solely on this defence.
They believe, however, that their findings could reveal a lot about how the immune system fights illness in the body.
Because Covid-19 is caused by a coronavirus, and other coronaviruses cause colds, researchers wondered if immunity to one could help with the other.
Researchers warn, however, that assuming that everyone who has just had a cold is automatically protected against Covid-19 is a “dangerous mistake,” as coronaviruses are not responsible for all colds.
The Imperial College London researchers wanted to know why some people develop Covid and others don’t after being exposed to it.
T-cells, a key component of the immune system, were the focus of their research. Some T-cells have the ability to kill any cells infected with a specific threat, such as a cold virus. Some T-cells remain in the body after the cold has passed as a memory bank, ready to form a response if the virus resurfaces.
A third of those who were not infected with Covid had high levels of specific memory T-cells in their bloodstream. According to the researchers, they were most likely produced after the body was infected with another closely related human coronavirus, most commonly a common cold.
According to the study, other factors like as ventilation and how contagious their home contact was may also influence whether someone caught the sickness.
Despite the fact that this was a small study, Dr. Simon Clarke of the University of Reading stated it contributes to our understanding of how our immune system fights the virus and could improve future immunizations.
He said, ” “It’s important not to over-interpret these numbers. It’s doubtful that someone who has died or has had a more serious infection has never experienced a coronavirus-caused cold.”
According to the author, it’s also a mistake to suppose that everyone who has just had a cold is immune to Covid-19, because coronaviruses are only responsible for 10-15% of all “colds.” The study’s lead author, Professor Ajit Lalvani, agreed that vaccines were necessary for protection. “Learning from what the body does well could help in the creation of future vaccinations,” he said.
Vaccines now available target spike proteins on the virus’s outer surface, but these spike proteins can change when new strains evolve.
Internal viral proteins, on the other hand, do not differ as much from one version to the next, hinting that vaccines that better harness the function of T-cells could provide broader, longer-lasting protection against Covid, he says.